Post-LGM glacial and geomorphic evolution of the Dora Baltea valley (western Italian Alps). (15th April 2022)

• Record Type: Journal Article
• Authors: Serra, Elena; Valla, Pierre G.; Gribenski, Natacha; Carcaillet, Julien; Deline, Philip
• Is Part Of: Quaternary science reviews. Volume 282(2022)
• Publication Date: 2022-04-15
• Subjects: Post-LGM glacial history -- Dora Baltea -- Western European Alps -- 10Be cosmogenic dating -- Optically-stimulated luminescence dating -- Ice surface reconstructions -- ELA -- Paraglacial processes; DB Dora Baltea -- LGM Last Glacial Maximum -- LIA Little Ice Age -- ELA Equilibrium-Line Altitude -- IMA Ivrea Morainic Amphitheatre -- KDE Normal Kernel Density Estimate -- THAR Toe-to-Headwall Altitude Ratio -- AAR Accumulation Area Ratio -- AABR Area-Altitude Balance Ratio; Geology, Stratigraphic -- Quaternary -- Periodicals; Stratigraphie -- Quaternaire -- Périodiques; 551.79
• DOI: 10.1016/j.quascirev.2022.107446
• Languages: English
• ISSNs: 0277-3791

Abstract

Abstract: Paleoglacial reconstructions in the European Alps have mainly focused on specific climatic periods such as the Last Glacial Maximum (LGM) or the Younger Dryas, with few studies investigating post-LGM Alpine glacier fluctuations encompassing broader temporal periods. In this study, we present a detailed reconstruction of the post-LGM glacial history of the Dora Baltea catchment, which hosted one of the main Quaternary glacial systems of the western European Alps. By combining existing and new chronological constraints from glacial and postglacial landforms/deposits into 2D and 3D ice surface reconstructions, we quantitatively reproduce the timing and ice-configuration of six LGM to early Holocene paleoglacial stages. Our deglaciation sequence along the Dora Baltea valley can be correlated with specific Lateglacial to Holocene paleoclimatic periods, in line with post-LGM glacier reconstructions from other Alpine areas. We estimated paleo equilibrium-line altitudes (ELAs) for each ice stage, using empirical ice-geometric methods. Our results indicate a low ELA sensitivity to ice decay during the early stages of deglaciation, despite significant glacier retreat from the piedmont into the massifs, suggesting a major role of catchment topography in controlling ELA estimates of large glacial systems. Finally, we provide chronological constraints for two major valley-slope collapse events, both postdating the Dora Baltea glacier withdrawal but implying different landscape response time to deglaciation as well as different triggering factors.